JP6638732B2 - Control system and control method - Google Patents

Description

  The present invention relates to a control system and the like.

  In recent years, there is a monitoring technology in which a server collects various kinds of environmental information such as temperature and humidity using a wireless sensor network in which a plurality of nodes performing wireless communication are arranged. Generally, each node is installed outdoors, and each node is operated by a battery and charges the battery using a solar panel.

  In a node installed outdoors, the remaining power of the battery fluctuates in accordance with changes in weather or sunshine, and software related to the operation cycle of each node is appropriately changed in order to suppress power depletion and the like. In addition to the above, software for operating a node may be changed as appropriate according to a request from an administrator or the like.

JP-A-2006-244120 JP 2006-209457 A JP 2006-260281 A

  However, in the above-described conventional technology, there is a problem that the cost for operating the system increases.

  For example, when each node is installed in a wide range, it is desirable to continue operation without updating software on the node once installed in order to reduce the burden on the administrator. To achieve this, software that can handle all possible combinations of environments and operations can be installed in the node in advance, or a software update function by remote control such as a general-purpose PC (Personal Computer) can be used. Will be implemented. However, the software and the software update function described above are complicated and have a large amount of implementation, which increases the cost of the node. In general, the quality of software deteriorates in proportion to the amount of software and the amount of control of the software. The quality will be reduced.

  On the other hand, if a simple implementation that does not support environmental variation and does not correspond to variations in operation is performed on the node, the function will be insufficient, and it will not be functionally suitable for a node installed outdoors. It will be something.

  In one aspect, an object of the present invention is to provide a control system and a control method capable of suppressing an increase in system operation cost.

  In the first case, the control system has a server and a plurality of nodes. The server has a transmission unit. The transmitting unit transmits, to the node, data of a command sequence in which a predetermined process to be executed by the node is described in combination with a sequential process and a loop process for repeatedly executing the sequential process. The node has a storage unit, a plurality of API units, and a control unit. The storage unit stores command string data received from the server. The API unit executes a predetermined sequential process. The control unit selects an API unit based on the command sequence stored in the storage unit, and causes the selected API unit to execute a sequential process and a loop process.

  It is possible to suppress an increase in cost for operating the system.

FIG. 1 is a diagram illustrating an example of a control system according to the present embodiment. FIG. 2 is a diagram for explaining power consumption of leaf nodes and power consumption of node nodes. FIG. 3 is a functional block diagram illustrating the configuration of the server according to the embodiment. FIG. 4 is a diagram (1) illustrating an example of a script corresponding to the control parameter A. FIG. 5 is a diagram (2) illustrating an example of the script corresponding to the control parameter A. FIG. 6 is a diagram (1) illustrating an example of a script corresponding to the control parameter B. FIG. 7 is a diagram (2) illustrating an example of the script corresponding to the control parameter B. FIG. 8 is a diagram (1) illustrating an example of a script for setting the role of a node. FIG. 9 is a diagram (2) illustrating an example of a script for setting the role of a node. FIG. 10 is a functional block diagram illustrating the configuration of the node according to the present embodiment. FIG. 11 is a diagram illustrating an example of power consumption of a node when the scripts a1 and a2 are executed. FIG. 12 is a diagram illustrating an example of power consumption of a node when the scripts b1 and b2 are executed. FIG. 13 is a flowchart illustrating an example of a processing procedure of the server. FIG. 14 is a flowchart illustrating an example of a processing procedure of the node. FIG. 15 is a diagram illustrating an example of a computer that executes a control program. FIG. 16 is a diagram illustrating a hardware configuration of a node.

  Hereinafter, embodiments of a control system and a control method according to the present invention will be described in detail with reference to the drawings. The present invention is not limited by the embodiment.

  FIG. 1 is a diagram illustrating an example of a control system according to the present embodiment. As illustrated in FIG. 1, the server includes a server 50, a gateway 60, and a sensor network 70. The sensor network 70 has nodes 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, and 100l. Here, the nodes 100a to 100l are shown as an example, but other nodes may be included. In the following description, the nodes 100a to 100l are collectively referred to as a node 100 as appropriate.

  The server 50 is connected to the gateway 60 via the network 5. The gateway 60 is connected to the sensor network 70. The nodes 100 included in the sensor network 70 are mutually connected by wireless communication.

  The server 50 is a device that transmits to the node 100 information of a command sequence in which a predetermined process to be executed by the node 100 is described by a combination of a sequential process and a loop process.

  The gateway 60 is a device that relays data transmitted and received between the server 50 and the sensor network 70.

  The node 100 is installed outdoors, is operated by a battery, and charges power to the battery using a solar panel. The node 100 has only a simple API (Application Programming Interface), a driver, and a control structure for sequential processing / loop processing. The node 100 executes the sequential processing and the loop processing based on the command sequence notified from the server 50.

  The nodes 100 on the sensor network 70 are classified into node nodes or leaf nodes due to differences in software functions. The node is a node 100 of the sensor network 70 that relays data. The node 100 not only transmits its own data, but also receives data from an adjacent node connected as a node, and transmits the received data to another adjacent node. Transfer to On the other hand, a leaf node is a node that only transmits its own data.

  The difference between a node node and a leaf node is only a setting of software, and any node 100 can be a node node or a leaf node. However, there is a large power difference between the power consumption of the leaf nodes and the power consumption of the node nodes.

  FIG. 2 is a diagram for explaining power consumption of leaf nodes and power consumption of node nodes. In FIG. 2, a graph 10A is a graph illustrating an example of a power waveform of a leaf node, in which a vertical axis indicates power and a horizontal axis indicates time. Graph 10B is a graph showing an example of the power waveform of the node, in which the vertical axis represents power and the horizontal axis represents time.

  The graph 10A will be described. The leaf node waits from a certain time to a time t1. The power consumption during standby is 2.1 mW. The leaf node performs a process of acquiring data from a sensor installed at the leaf node from time t1 to time t2. The leaf node performs pre-data transmission processing from time t2 to time t3. The power consumption when executing the data transmission pre-processing is 98.6 mW. The leaf node performs data transmission between time t3 and time t4. Power consumption during data transmission is 126.4 mW. The leaf node performs post-processing from time t5 to time t6. At a time after the post-processing, the power consumption is 30.6 mW. The leaf node enters the standby state again after time t6.

  The graph 10B will be described. The node waits for data reception from an adjacent node from a certain time to a time t7. The power consumption during standby for data reception is 98.6 mW. The node node performs data transmission from time t7 to time t8. Power consumption during data transmission is 126.4 mW.

  Comparing the graph 10A with the graph 10B, for example, in the leaf node, the power consumption is increased only for about 10 ms from the time t1 when data acquisition is started from the sensor to the time t6 when the post-processing is completed. The power consumption at the time of becomes smaller. On the other hand, the node node always consumes a large amount of power.

  The node 100 configuring the sensor network 70 is installed outdoors and is generated by a solar panel and charged by a battery. However, since the power consumption of the node is large, when the node 100 is located in a shade or in bad weather. Means that the power of the node is depleted.

  Here, it is possible to construct a control algorithm by taking into account the weather and shade conditions, and by taking into account the imbalance in power consumption due to the topology of the sensor network 70 that becomes leaves and nodes. However, when actually placed in a natural environment, there are some events that cannot be understood without actually operating the system because of complicated factors. For this reason, it is difficult to operate the node 100 independently using a control algorithm such as “suspend temporarily because the power threshold value has dropped below PP under the conditions of XX, YY, and ZZ”.

  Next, the configuration of the server 50 shown in FIG. 1 will be described. FIG. 3 is a functional block diagram illustrating the configuration of the server according to the embodiment. As shown in FIG. 3, the server 50 has a communication unit 51, a storage unit 52, and a control unit 53.

  The communication unit 51 is a processing unit that executes data communication with the node 100 of the sensor network 70 via the network 5 and the gateway 60. The communication unit 51 corresponds to, for example, a communication device. The control unit 53 described later exchanges data with the node 100 of the sensor network 70 via the communication unit 51.

  The storage unit 52 has a power data table 52b. The storage unit 52 corresponds to, for example, a storage device such as a semiconductor memory device such as a random access memory (RAM), a read only memory (ROM), and a flash memory.

  The power data table 52b is a table that stores identification information for uniquely identifying the node 100 and power data in association with each other. For example, the power data is information on the amount of power stored in the battery of each node 100.

  The control unit 53 includes a power data acquisition unit 53a, a script generation unit 53b, and a transmission unit 53c. The control unit 53 corresponds to, for example, an integrated device such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 53 corresponds to, for example, an electronic circuit such as a CPU or an MPU (Micro Processing Unit).

  The power data acquisition unit 53a is a processing unit that acquires power data from each node 100. The power data acquisition unit 53a stores the power data acquired from the node 100 in the power data table 52b in association with the identification information of the node 100.

  The script generation unit 53b is a processing unit that generates a predetermined process to be executed by the node 100 as information of a sequential process and a command sequence for repeatedly executing the sequential process. For example, the command sequence is described in, for example, a script language. In the following description, a command sequence generated by the script generation unit 53b is appropriately referred to as a script. The script generation unit 53b outputs script information to the transmission unit 53c.

  The transmission unit 53c is a processing unit that transmits information of the script received from the script generation unit 53b to each node 100 of the sensor network 70. In the following description, script information will be referred to as script information as appropriate.

  Subsequently, information of the command sequence generated by the script generation unit 53b described above will be specifically described.

First, a script transmitted when the server 50 operates each node 100 of the sensor network 70 by default will be described. The information of the control parameter A configuring the default operation state of the sensor network 70 is A1, A2, A3 shown below.
A1: Sampling is performed every 20 seconds.
A2: The state of A1 is maintained for one minute.
A3: Sleep for 9 minutes.

  When operating the sensor network 70 in the default operation state, the script generation unit 53b of the server 50 generates a script corresponding to the control parameter A. Scripts corresponding to the control parameter A are a script a1 shown in FIG. 4 and a script a2 shown in FIG. 4 and 5 are diagrams illustrating an example of a script corresponding to the control parameter A.

  The first line of the script a1 illustrated in FIG. 4 indicates the node 100 that executes the command. The first line is “Target: All end device”, and the node 100 that executes the command is all leaf nodes included in the sensor network 70. The contents from the second line to the fifth line of the script a1 mean that “processing of {sensing → transmitting the sensed data} is performed every 20 seconds”. The leaf node that has acquired the script a1 performs sensing every 20 seconds, and transmits the sensed data to the server 50.

  The first line of the script a2 illustrated in FIG. 5 indicates the node 100 that executes the command. The first line is “Target: All end device”, and the node 100 that executes the command is all leaf nodes included in the sensor network 70. The contents of the second and third lines of the script a2 mean “sleep for 9 minutes”. For example, upon receiving the script a2, the node 100 that has been performing the loop operation based on the script a1 enters a sleep state for 9 minutes from the time of receiving the script a2, and after returning from the sleep state, returns to the loop operation based on the script a1 again. .

  Note that the transmitting unit 53c transmits the script a1 to the node 100 and then transmits the script a2 every 10 minutes, whereby each node 100 can execute the following processing. That is, the node 100 continues the process of transmitting the sensed data to the server 50 every 20 seconds for one minute. Then, the node 100 enters the sleep state for 9 minutes, and performs sampling every 20 seconds again.

  Next, a script that the server 50 transmits to a node 100 where power is likely to be depleted will be described. Here, a node 100 whose power is likely to be depleted is referred to as a node 100X. The node 100X corresponds to any of the nodes 100a to 100l illustrated in FIG. If the server 50 stops the node 100X, the node will be lost, and a problem will occur in topology. Therefore, the server 50 keeps operating the node 100X as much as possible.

  For example, when the server 50 operates the node 100X based on the expected value of return from temporary power generation failure or the time of sunrise / sunset from the statistical information of the power generation state of each node 100, It is determined whether the power depletion state of the node 100X can be resolved.

  For example, the script generation unit 53b of the server 50 generates a script of a command sequence in which sampling in one cycle operation is thinned out from three times to one time. With this script, the power consumption of the node 100X is reduced to 1/3, and the time until the power of the node 100X is exhausted is lengthened. For example, if the operations shown in FIGS. 4 and 5 are continued, the power is depleted before the sun rises, but the operation can be continued until the sun rises by thinning out the number of samplings. The power of the battery of the node 100X is charged by the subsequent sunshine, and the danger of power depletion can be resolved.

For example, information on the control parameter B transmitted to the node 100X to prevent power depletion is B1, B2, and B3 shown below.
B1: Sampling is performed every 60 seconds.
B2: State 1 of B1 is maintained for a minute.
B3: Sleep for 9 minutes.

  The script generation unit 53b of the server 50 generates a script corresponding to the control parameter B. Scripts corresponding to the control parameter B are a script b1 shown in FIG. 6 and a script b2 shown in FIG. 6 and 7 are diagrams illustrating an example of a script corresponding to the control parameter B.

  The first line of the script b1 illustrated in FIG. 6 indicates the node 100 that executes the command. The first line is “Target: Node X”, and the node 100 that executes the command is the node 100X included in the sensor network 70. The contents of the script b1 from the second line to the fifth line mean that "processing of {sensing → transmitting sensed data} is performed every 60 seconds". The node 100X that has acquired the script b1 performs sensing every 60 seconds and transmits the sensed data to the server 50.

  The first line of the script b2 shown in FIG. 7 indicates the node 100 that executes the command. The first line is “Target: Node ALL end device”, and the nodes 100 that execute the command are all the nodes 100 included in the sensor network 70. The contents of the second and third lines of the script b2 mean “sleep for 9 minutes”. For example, upon receiving the script b2, the node 100X that has been performing the loop operation based on the script b1 enters a sleep state for 9 minutes from the time of receiving the script b2, and after returning from the sleep state, returns to the loop operation based on the script b1 again. .

  In addition, after transmitting the script b1 to the node 100X, the transmitting unit 53c transmits the script b2 every 10 minutes, whereby each node 100X can execute the following processing. That is, the node 100X continues the process of transmitting the sensed data to the server 50 every 60 seconds for one minute. Then, the node 100X enters the sleep state for 9 minutes, and performs sampling every 60 seconds again.

  In the above example, the transmitting unit 53c transmits the scripts b1 and b2 to the node 100X where power is likely to be depleted to prevent the power from being depleted. However, the transmitting unit 53c transmits the other scripts to the node 100X. May be sent to For example, when the role of the node 100X is a node, the transmitting unit 53c may reduce power consumption by changing the role of the node 100X to a leaf node.

  Here, for example, when the power amount of the node 100X falls below the threshold, the server 50 determines that the power of the node 100X is about to be exhausted. For example, the server 50 may set the threshold based on the following considerations 1 to 5.

Consideration 1: Is the state where the threshold is cut off due to operation at successive node nodes?
Consideration 2: Is the power generation state reduced by sunset, and is it expected to be generated the next morning?
Consideration 3: Is the power generation state reduced due to sudden weather change?
Consideration 4: Is it originally installed in the shade and the power generation state is constantly bad?
Consideration 5: A combination of considerations 1-4 and whether the node is a leaf node or a node.

  Subsequently, a case where the server 50 classifies each node 100 into a plurality of groups and transmits a different script for each group will be described. For example, the server 50 changes the role assignment between the leaf nodes and the node nodes on a group basis. By changing the role assignment between the leaf nodes and the node nodes on a group basis, it is possible to eliminate the bias in the power consumption of each node 100.

  Here, it is assumed that the node 100 is classified into a group M or a group N. 8 and 9 are diagrams illustrating an example of a script for setting the role of a node.

  The first line of the script c1 illustrated in FIG. 8 indicates the node 100 that executes the commands of the second to fourth lines. The first line is “Target: Node group M”, and the node 100 executing the command is the node 100 belonging to the group M of the sensor network 70. The contents of the second to fourth lines of the script c1 mean that “the role of the node 100 is a leaf node (End device)”. That is, upon receiving the script c1, the node 100 belonging to the group M sets the role to a leaf node.

  The fifth line of the script c1 indicates the node 100 that executes the commands on the sixth to eighth lines. The fifth line is “Target: Node group N”, and the node 100 executing the command is the node 100 belonging to the group N of the sensor network 70. The contents of the sixth to eighth lines of the script c1 mean that “the role of the node 100 is a node (Router)”. That is, when the node 100 belonging to the group N receives the script c1, the role is set to the node.

  The ninth line of the script c1 indicates the node 100 that executes the commands on the tenth to twelfth lines. The ninth line is “Target: All node”, and the nodes 100 executing the command are all the nodes 100 included in the sensor network 70. The contents from the 10th line to the 12th line of the script c1 mean "rebuild the network".

  The first line of the script c2 shown in FIG. 9 indicates the node 100 that executes the commands of the second to fourth lines. The first line is “Target: Node group N”, and the node 100 executing the command is the node 100 belonging to the group N of the sensor network 70. The contents of the second to fourth lines of the script c2 mean that “the role of the node 100 is a leaf node (End device)”. That is, upon receiving the script c2, the node 100 belonging to the group N sets the role to a leaf node.

  The fifth line of the script c2 indicates the node 100 that executes the commands on the sixth to eighth lines. The fifth line is “Target: Node group M”, and the node 100 that executes the command is the node 100 belonging to the group M of the sensor network 70. The contents of the script c2 from the 6th line to the 8th line mean that "the role of the node 100 is a node (Router)". That is, when the node 100 belonging to the group M receives the script c2, the role is set to the node.

  The ninth line of the script c2 indicates the node 100 that executes the commands on the tenth to twelfth lines. The ninth line is “Target: All node”, and the nodes 100 executing the command are all the nodes 100 included in the sensor network 70. The contents of the script c2 from the 10th line to the 12th line mean “rebuild the network”.

  Next, the configuration of the node 100 shown in FIG. 1 will be described. FIG. 10 is a functional block diagram illustrating the configuration of the node according to the present embodiment. As shown in FIG. 10, the node 100 has API units 110a, 110b, 110c, 110d and drivers 120a, 120b, 120c, 120d. The node 100 may have an API unit other than the API units 110a to 110d. The node 100 may have a driver other than the drivers 120a to 120d. The node 100 has a storage unit 130 and a control unit 140.

  The API unit 110a is a processing unit that, when receiving a sensing execution command from the control unit 140, controls the driver 120a to acquire environment data from a sensor (not shown). The environmental data includes, for example, data such as temperature and humidity.

  The driver 120a is connected to the sensor. The driver 120a is a device driver that acquires environment data from a sensor and outputs the environment data to the API unit 110a. The sensors correspond to temperature sensors, humidity sensors, and the like.

  The API unit 110b is a processing unit that controls the driver 120b and transmits specified data when an execution command of data transmission is received from the control unit 140. For example, the API unit 110b transmits environment data, power data, script data, and the like. When receiving an execution command for data reception from the control unit 140, the API unit 110b controls the driver 120b to perform data reception.

  The driver 120b is connected to a communication device. The driver 120b is a device driver that operates the communication device to transmit and receive data.

  When a sleep execution command is received from the control unit 140, the API unit 110c controls the driver 120c to control power supply to the node 100. Note that the API unit 110c and the driver 120c always receive power supply from the power module that supplies power, and the power supply to the API unit 110c and the driver 120c continues even if the power supply to the node 100 is stopped. I do. For example, when the API execution unit 110c receives the sleep execution command for X minutes, the API unit 110c stops the power supply to the node 100 for X minutes from the timing when the sleep execution command is received, and then turns off the power supply. To resume.

  The API unit 110d is a processing unit that controls the driver 120d to detect power data of a battery (not shown) when receiving an execution command of power data detection from the control unit 140.

  Driver 120d is connected to the battery. The power data of the battery is detected, and the detected power data is output to the API unit 110d.

  The storage unit 130 has an identification information management table 130a and script information 130b. For example, the storage unit 130 corresponds to a semiconductor memory device such as a random access memory (RAM), a read only memory (ROM), or a flash memory, or a storage device such as a hard disk drive (HDD).

  The identification information management table 130a is information including node identification information for identifying the node 100, role identification information for identifying the role of the node 100, and group identification information for identifying the group to which the node 100 belongs. Among them, the role identification information is set in either a leaf node (end device) or a node (Router).

  The script information 130b corresponds to script information transmitted from the server 50 to the node 100. For example, the information on the script is the information on the command sequence shown in FIGS.

  The control unit 140 is a processing unit that executes a predetermined process by controlling the API units 110a to 110d based on the script information 130b. The control unit 140 corresponds to an integrated device such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 140 corresponds to, for example, an electronic circuit such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit).

  When receiving the script information 130b via the API unit 110b, the control unit 140 stores the received script information 130b in the storage unit 130. The control unit 140 refers to the identification information management table 130a and, when the node 100 is a node, transmits the script information 130b to the adjacent node 100 via the API unit 110b.

  Hereinafter, an example of a process executed by the control unit 140 based on the script information 130b will be described. When the Target included in the script information 130b corresponds to each piece of identification information in the identification information management table 130a, the control unit 140 sequentially executes the corresponding command sequence. For example, when the identification information of the node 100 specified by Target matches the node identification information of the identification information management table 130a, the control unit 140 executes the corresponding command sequence. When the role of the node 100 designated by Target matches the role identification information of the identification information management table 130a, the control unit 140 executes the corresponding command sequence. When the identification information of the group of the node 100 specified by Target matches the group identification information of the identification information management table 130a, the control unit 140 executes the corresponding command sequence. When the target is “All node”, the control unit 140 sequentially executes the corresponding command sequence regardless of the identification information in the identification information management table 130a.

  The processing when the control unit 140 executes the scripts a1 and a2 shown in FIGS. 4 and 5 will be described. As an example, assume that the role identification information of the identification information management table 130a is “leaf node (end device)”. In FIG. 4, since the Target of the script a1 matches the role identification information of the identification information management table 130a, the control unit 140 executes the processing from the second line to the fifth line. Specifically, the control unit 140 executes a process of outputting a sensing execution command to the API unit 110a and outputting a data transmission execution command to the API unit 110b every 20 seconds. For example, data transmitted by data transmission corresponds to environment data acquired by the API unit 110a.

  In FIG. 5, since the Target of the script a2 matches the role identification information of the identification information management table 130a, the control unit 140 executes the processing in the second and third lines. Specifically, the control unit 140 outputs a sleep (9-minute sleep) execution command to the API unit 110c.

  FIG. 11 is a diagram illustrating an example of power consumption of a node when the scripts a1 and a2 are executed. The vertical axis in FIG. 11 indicates power consumption, and the horizontal axis indicates time. For example, the example illustrated in FIG. 11 illustrates a case where the control unit 140 periodically executes a process of starting the process of the script a2 one minute after the process of the script a1 is started. As shown in FIG. 11, a sensing execution command and a data transmission execution command are output every 20 seconds, so that sensing and data transmission are executed three times in one minute.

  Here, it is assumed that the time required for sensing and data transmission is 10 ms. Then, the node 100 operates for 30 ms in one cycle and operates for 180 ms in one hour. Assuming that the power consumption required for sensing and data transmission is 100 mW, the power consumption of the node 100 per hour is 100 mW × 180 ms / 3600 s = 5 × 10 ＾ (− 3) mW. For example, when the remaining power of the battery is 15 × 10 ＾ (− 3) mW, it can be understood that the power of this node 100 is depleted in 3 hours.

  Processing when the control unit 140 executes the scripts b1 and b2 shown in FIGS. 6 and 7 will be described. As an example, the node identification information of the identification information management table 130a is “node 100X”, and the role identification information is “leaf node (end device)”. In FIG. 6, since the Target of the script b1 matches the node identification information of the identification information management table 130a, the control unit 140 executes the processing from the second line to the fifth line. Specifically, the control unit 140 performs a process of outputting a sensing execution command to the API unit 110a and outputting a data transmission execution command to the API unit 110b every 60 seconds. For example, data transmitted by data transmission corresponds to environment data acquired by the API unit 110a.

  In FIG. 7, since the Target of the script b2 matches the role identification information of the identification information management table 130a, the control unit 140 executes the processing in the second and third lines. Specifically, the control unit 140 outputs a sleep (9-minute sleep) execution command to the API unit 110c.

  FIG. 12 is a diagram illustrating an example of power consumption of a node when the scripts b1 and b2 are executed. The vertical axis in FIG. 12 indicates power consumption, and the horizontal axis indicates time. For example, the example illustrated in FIG. 12 illustrates a case where the control unit 140 periodically executes a process of starting the process of the script b2 one minute after the process of the script b1 is started. As shown in FIG. 12, a sensing execution command and a data transmission execution command are output every 60 seconds, so that sensing and data transmission are performed once during one second.

  Here, it is assumed that the time required for sensing and data transmission is 10 ms. Then, the node 100 operates for 10 ms in one cycle and operates for 60 ms in one hour. Assuming that the power consumption required for sensing and data transmission is 100 mW, the power consumption of the node 100 per hour is 100 mW × 60 ms / 3600 s = 1.67 × 10 ＾ (− 3) mW. For example, when the remaining power of the battery is 15 × 10 ＾ (− 3) mW, it can be understood that the power of this node 100 is depleted in about 9 hours. For example, as compared with the case described with reference to FIG. 11, in FIG. 12, the time when the power is depleted can be extended about three times.

  The processing when the control unit 140 executes the script c1 shown in FIG. 8 will be described. As an example, assume that the group identification information in the identification information management table 130a is “group M”. In FIG. 8, the control unit 140 executes the command sequence from the second line to the fourth line because the Target on the first line matches the group identification information. Specifically, the control unit 140 sets the role identification information of the identification information management table 130a to “End device”.

  The control unit 140 skips the execution of the command sequence from the sixth line to the eighth line because the target on the fifth line does not match the group identification information.

  The control unit 140 executes the command sequence from the tenth line to the twelfth line because the target on the ninth line is “All node”. Specifically, the control unit 140 executes network reconfiguration. For example, the control unit 140 transmits and receives a hello packet to and from the adjacent node 100 using the API unit 110b, and reconfigures the sensor network 70. The process in which the control unit 140 reconstructs the sensor network 70 may execute the same process as that of the related art.

  The processing when the control unit 140 executes the script c2 shown in FIG. 9 will be described. As an example, assume that the group identification information in the identification information management table 130a is “group M”. The control unit 140 skips the execution of the command sequence from the second line to the fourth line because the Target on the first line does not match the group identification information.

  The control unit 140 executes the command sequence from the sixth line to the eighth line because the target on the fifth line matches the group identification information. Specifically, the control unit 140 sets the role identification information of the identification information management table 130a to “Router”.

  The control unit 140 executes the command sequence from the tenth line to the twelfth line because the target on the ninth line is “All node”. Specifically, the control unit 140 executes network reconfiguration. For example, the control unit 140 transmits and receives a hello packet to and from the adjacent node 100 using the API unit 110b, and reconfigures the sensor network 70.

  Incidentally, the script information 130b may store a command sequence for periodically transmitting power data to the server 50, in addition to the command sequence described above. The control unit 140 transmits the power string to the server 50 by executing the command sequence and outputting the command to the API units 110b and 110d.

  Next, a processing procedure of the server 50 and the node 100 of the control system according to the present embodiment will be described. FIG. 13 is a flowchart illustrating an example of a processing procedure of the server. As shown in FIG. 13, the server 50 constructs the sensor network 70 by transmitting script information for constructing the network to each node 100 of the sensor network 70 (Step S101).

  The server 50 receives the power data from the node 100 (Step S102). The server 50 determines whether the power is less than the threshold (Step S103). If the power is not less than the threshold (No at Step S104), the server 50 proceeds to Step S102 again.

  On the other hand, if the power is less than the threshold value (step S104, Yes), the server 50 generates script information (step S105). The server 50 transmits the script information to the node 100 (Step S106).

  FIG. 14 is a flowchart illustrating an example of a processing procedure of the node. As illustrated in FIG. 14, the control unit 140 of the node 100 receives the script information 130b from the server 50 (Step S201). The control unit 140 stores the script information 130b in the storage unit 130 (Step S202).

  The control unit 140 determines whether the role identification information is "Router (node)" (step S203). When the role identification information is “Router” (Step S203, Yes), the control unit 140 transmits the script information 130b to the adjacent node (Step S204). If the role identification information is not “Router” (No at Step S203), the control unit 140 proceeds to Step S205.

  The control unit 140 compares the Target of the script information 130b with the identification information management table 130a to specify a command string to be executed (Step S205). The control unit 140 outputs an execution command corresponding to the command sequence to the corresponding API unit. When the command is a loop process, the control unit 140 repeatedly outputs an execution command to the API unit (Step S206).

  Next, an example of a computer and a hardware configuration for executing a control program that realizes the same functions as those of the server 50 described in the above embodiment will be described. FIG. 15 is a diagram illustrating an example of a computer that executes a control program.

  As shown in FIG. 15, the computer 300 includes a CPU 301 that executes various arithmetic processing, an input device 302 that receives input of data from a user, and a display 303. In addition, the computer 300 includes a reading device 304 that reads a program or the like from a storage medium, and an interface device 305 that exchanges data with another computer via a network. Further, the computer 300 has a RAM 306 for temporarily storing various information, and a hard disk device 307. Each of the devices 301 to 307 is connected to the bus 308.

  The hard disk device 307 has a power data acquisition program 307a, a script generation program 307b, and a transmission program 307c. The CPU 301 reads the power data acquisition program 307a, the script generation program 307b, and the transmission program 307c and expands them on the RAM 306. The power data acquisition program 307a functions as a power data acquisition process 306a. The script generation program 307b functions as a script generation process 306b. The transmission program 307c functions as a transmission process 306c. For example, the power data acquisition process 306a corresponds to the power data acquisition unit 53a. The script generation process 306b corresponds to the script generation unit 53b. The transmission process 306c corresponds to the transmission unit 53c.

  The power data acquisition program 307a, the script generation program 307b, and the transmission program 307c do not necessarily need to be stored in the hard disk device 307 from the beginning. For example, each program is stored in a “portable physical medium” such as a flexible disk (FD), a CD-ROM, a DVD disk, a magneto-optical disk, or an IC card inserted into the computer 300. Then, the computer 300 may read and execute the power data acquisition program 307a, the script generation program 307b, and the transmission program 307c.

  Next, an example of a hardware configuration of the node 100 described in the above embodiment will be described. FIG. 16 is a diagram illustrating a hardware configuration of a node. For example, the node 100 includes an energy harvesting element 10, a power module 11, a battery 12, a sensor device 13, an I / O (Input Output) 14, an RF (Radio Frequency) 15, a timer 16, a memory 17, and a CPU 18.

  The energy harvesting element 10 is an element that generates weak power using environmental radio waves, temperature, and the like, and corresponds to, for example, a solar panel or the like.

  The power module 11 is a device that is connected to the energy harvesting element 10 and the battery 12, and supplies and stops power to the I / O 14, the RF 15, the timer 16, the memory 17, and the CPU 18 of the node 100. The power module 11 has a timer 11a and a PMU (Power Management Unit) 11b. The timer 11a is a timer that outputs time information to the PMU 11b. The PMU 11b supplies and stops power to the I / O 14, the RF 15, the timer 16, the memory 17, and the CPU 18 of the node 100. For example, when an execution command to sleep for 9 seconds is received from the CPU 18, the power supply to the I / O 14, the RF 15, the timer 16, the memory 17, and the CPU 18 is stopped for 9 seconds, thereby causing the node 100 to sleep. Transition to the state. The battery 12 is a device that stores electric power generated from the energy harvesting element 10.

  The sensor device 13 is a device that senses various types of environmental data. The I / O 14 is a device that acquires environmental data from the sensor device 13. The RF 15 is a communication device that performs wireless communication with another device. The timer 16 is a timer that outputs time information to the CPU 18. The memory 17 is a storage device that stores various types of information, and stores, for example, the identification information management table 130a and the script information 130b shown in the storage unit 130 in FIG. The CPU 18 is a device corresponding to the control unit 140 shown in FIG.

  Next, effects of the control system according to the present embodiment will be described. Each node 100 constituting the sensor network 70 has only a simple API unit, a driver, and a control structure for sequential processing / loop processing, and script information combining simple sequential processing / loop processing is sent from the server 50 to the node 100. Since the notification is executed, the operation cost of the sensor network 70 can be reduced.

  For example, if all logic is mounted on the node side as in a conventional node, the node uses a data capacity of 2 MBytes. On the other hand, by transmitting the script information to the node 100 and operating it as in the present embodiment, the node 100 can use the data capacity of 8 kByte.

  In general, the potential bug ratio of software increases in proportion to the amount of implementation and the amount of control branches, but the script information used in this embodiment has a small data amount, so the potential bug ratio is compared with that of a conventional node. Can be reduced.

  Further, in the present embodiment, based on the power data acquired from the node 100, the node 100 where power depletion is likely to be specified is specified, and the role and operation pattern of the node 100 are changed using the script information. Depletion can be prevented beforehand. Further, the determination logic can be dynamically changed.

  Further, when the role is a node, the node 100 according to the present embodiment transmits the script information to each node 100 of the sensor network 70 in order to transfer the command string data received from the server 50 to the adjacent node. Can be notified.

  Further, the node 100 according to the present embodiment has the group identification information in the identification information management table 130a, and when the group specified by Target of the script information matches the group identification information, the script command sequence Execute For this reason, the server 50 can change the role of the node 100 and the operation pattern collectively for each group.

50 server 60 gateway 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, 100j, 100k, 100l Node

Claims (5)

A control system having a plurality of nodes and a server configuring a network,
The server is
A command sequence in which a predetermined process to be executed by the node is described as a combination of a sequential process and a loop process for repeatedly executing the sequential process. A generation unit that generates data of the command sequence in which the execution frequency of the loop processing is adjusted based on the statistical information of the state and the time of sunshine sunset;
A transmission unit that transmits the data of the command sequence generated by the generation unit to the node,
The node is
Powered by a battery powered by solar panels,
A storage unit for storing the data of the command sequence received from the server,
A plurality of API (Application Programming Interface) units for executing predetermined sequential processing;
A control unit that selects the API unit based on a command sequence stored in the storage unit, and causes the selected API unit to execute a sequential process and a loop process.   The data of the command string transmitted by the transmission unit, the node acquires data from an external device connected to the node, and the node performs data communication with the server via the network, A process of controlling the power to be supplied to the node is command sequence data describing a combination of a sequential process and a loop process, wherein the plurality of API units include an API unit that acquires data from an external device; The control system according to claim 1, further comprising: an API unit that performs data communication with the server via a network; and an API unit that controls power supplied to the node.   The control system according to claim 1, wherein the control unit controls the API unit to transfer command sequence data received from the server to an adjacent node.   The storage unit stores identification information for identifying a group to which the node belongs, and the control unit matches the identification information given to the data of the command string with the identification information stored in the storage unit. The control system according to claim 1, wherein when executing, the data of the command sequence is executed. A server, the data of a command sequence described by a combination of a sequential process and a loop process for repeatedly executing the predetermined process to be executed by each node constituting the network, the power stored in the battery of the node Based on the information of the amount, the statistical information of the power generation state of the node, and the time of sunshine sunset, the data of the command sequence in which the execution frequency of the loop processing is adjusted is generated,
Transmitting the generated data of the command sequence to the node,
The node that is driven by a battery powered by solar panels, and stores data of the command string received from the server to the storage device,
A plurality of API (Application Programming Interface) sections for executing predetermined sequential processing are selected based on a command sequence stored in the storage device, and the selected API sections execute sequential processing and loop processing. A control method characterized by performing:

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